GPS scintillations associated with cusp dynamics and polar cap patches

This paper investigates the relative scintillation level associated with cusp dynamics (including precipitation, flow shears, etc.) with and without the formation of polar cap patches around the cusp inflow region by the EISCAT Svalbard radar (ESR) and two GPS scintillation receivers. A series of polar cap patches were observed by the ESR between 8:40 and 10:20 UT on December 3, 2011. The polar cap patches combined with the auroral dynamics were associated with a significantly higher GPS phase scintillation level (up to 0.6 rad) than those observed for the other two alternatives, i.e., cusp dynamics without polar cap patches, and polar cap patches without cusp aurora. The cusp auroral dynamics without plasma patches were indeed related to GPS phase scintillations at a moderate level (up to 0.3 rad). The polar cap patches away from the active cusp were associated with sporadic and moderate GPS phase scintillations (up to 0.2 rad). The main conclusion is that the worst global navigation satellite system space weather events on the dayside occur when polar cap patches enter the polar cap and are subject to particle precipitation and flow shears, which is analogous to the nightside when polar cap patches exit the polar cap and enter the auroral oval

Scintillation and irregularities from the nightside part of a Sun-aligned polar cap arc

In this paper we study the presence of irregularities and scintillation in relation to the nightside part of a long-lived, Sun-aligned transpolar arc on 15 January 2015. The arc was observed in DMSP UV and particle data and lasted at least 3 h between 1700 and 2000 UT. The arc was more intense than the main oval during this time. From all-sky imagers on Svalbard we were able to study the evolution of the arc, which drifted slowly westward toward the dusk cell. The intensity of the arc as observed from ground was 10-17 kR in 557.7 nm and 2-3.5 kR in 630.0 nm, i.e., significant emissions in both green and red emission lines. We have used high-resolution raw data from global navigation satellite systems (GNSS) receivers and backscatter from Super Dual Auroral Radar Network (SuperDARN) radars to study irregularities and scintillation in relation to the polar cap arc. Even though the literature has suggested that polar cap arcs are potential sources for irregularities, our results indicate only very weak irregularities. This may be due to the background density in the northward IMF polar cap being too low for significant irregularities to be created

Steepening Plasma Density Spectra in the Ionosphere: The Crucial Role Played by a Strong E-Region

Based on the Swarm 16 Hz Advanced Plasma Density data set, and using the Swarm A satellite, we apply automatic detection of spectral breaks in seven million sampled plasma density power spectra in the high-latitude F-region ionosphere. This way, we survey the presence of plasma irregularity dissipation due to an enhanced E-region conductance, caused both by solar photoionization and particle precipitation. We introduce a new quantity named the steepening slope index (SSI) which we use to estimate the occurrence rate of break-points in sampled plasma densities. We provide an interpretation of SSI in the context of solar photoionization-induced conductance enhancements of the E-region. We present a comprehensive climatology of the SSI occurrence rate, along with statistics documenting characteristic high-latitude plasma density spectra. In the absence of steepening, the typical spectral index is 2.1. When density spectra steepen, the index is typically 1.6 at large scales, and 2.7 at small scales. We discuss the impact of high-energy deeply penetrating electron precipitation in the diffuse aurora, and precipitating electrons in the aurora at large. Here, a key finding is that near the cusp, where the F-region conductance is enhanced, spectra tend not to steepen. We find that both the diffuse and discrete aurora are modulating F-region plasma irregularity dissipation through an enhancement of E-region conductance, highlighting the role played by factors other than solar zenith angle in high-latitude plasma dynamics. The influence of E-region conductance on spectral shapes indicates the need for a new discussion of how particle precipitation can structure the local winter high-latitude F-region ionosphere

NanoMagSat, a nanosatellite LEO constellation for monitoring Earth's magnetic field and ionospheric environment

International audienceThe geomagnetic field has been continuously monitored from low-Earth orbit (LEO) since 1999, complementing ground-based observatory data by providing calibrated scalar and vector measurements with global coverage. The successful ESA Swarm constellation is expected to remain in operation until at least 2025. Further monitoring the field from space with high-precision absolute magnetometry is of critical importance for improving our understanding of the dynamics of the multiple components of this field, as well as that of the ionospheric environment. The NanoMagSat project aims to deploy and operate a new LEO constellation with a current baseline of three identical 16U nanosatellites, using two 60° inclined orbits offset by 90° RAAN and one polar orbit, and hosting an innovative payload suite. This will consist of an advanced miniaturized absolute scalar and self-calibrated vector magnetometer (MAM) combined with a set of accurate star trackers (STR), a compact high-frequency field magnetometer (HFM), a multi-needle Langmuir probe (m-NLP) and dual frequency GNSS receivers. This payload suite will acquire high-precision/resolution oriented absolute vector magnetic data at 1 Hz sampling rate (for global magnetic field modelling purposes), very low noise scalar and vector magnetic field at 2 kHz (for ELF signal detection and down to decameter-scale local electrical currents monitoring), electron density data at 2 kHz (for very small scale plasma density investigations), as well as electron temperature at 1 Hz. GNSS receivers will also allow top-side TEC and radio-occultation profiles to be recovered. The three-satellite constellation design is such that all local times at all geographic locations between 60°N and 60°S will be covered in a little more than one month, much faster than Swarm, which the NanoMagSat is also designed to complement for even better coverage, should Swarm still be in operation at the time of launch. After an initial Phase 0 study carried out with CNES support, NanoMagSat was next proposed in response to the ESA Scout call in 2019 and selected for a consolidation study, which ran through 2020. It is currently undergoing an ESA-funded 18 month phase of Risk Retirement Activities (RAA), aiming at being ready for a possible final selection in 2023, targeting a launch in 2025. This presentation will report on the way the project is currently moving forward technically, programmatically and scientifically. NanoMagSat is designed to complement and improve on many of the science goals of the Swarm mission at a much lower cost, also bringing innovative science capabilities for ionospheric investigations. It aims at forming the basis of a permanent collaborative INTERMAGSAT constellation of nanosatellites for low-cost long-term monitoring of the geomagnetic field and ionospheric environment from space, complementing the INTERMAGNET network of ground-based magnetic observatories. This presentation is also meant to initiate a discussion on the way the NanoMagSat project could contribute to the goals of the COSPAR Task Group on the Establishment of a Constellation of Small Satellites (COSPAR TGCSS)

NanoMagSat, a nanosatellite LEO constellation for monitoring Earth's magnetic field and ionospheric environment

International audienceThe geomagnetic field has been continuously monitored from low-Earth orbit (LEO) since 1999, complementing ground-based observatory data by providing calibrated scalar and vector measurements with global coverage. The successful ESA Swarm constellation is expected to remain in operation until at least 2025. Further monitoring the field from space with high-precision absolute magnetometry is of critical importance for improving our understanding of the dynamics of the multiple components of this field, as well as that of the ionospheric environment. The NanoMagSat project aims to deploy and operate a new LEO constellation with a current baseline of three identical 16U nanosatellites, using two 60° inclined orbits offset by 90° RAAN and one polar orbit, and hosting an innovative payload suite. This will consist of an advanced miniaturized absolute scalar and self-calibrated vector magnetometer (MAM) combined with a set of accurate star trackers (STR), a compact high-frequency field magnetometer (HFM), a multi-needle Langmuir probe (m-NLP) and dual frequency GNSS receivers. This payload suite will acquire high-precision/resolution oriented absolute vector magnetic data at 1 Hz sampling rate (for global magnetic field modelling purposes), very low noise scalar and vector magnetic field at 2 kHz (for ELF signal detection and down to decameter-scale local electrical currents monitoring), electron density data at 2 kHz (for very small scale plasma density investigations), as well as electron temperature at 1 Hz. GNSS receivers will also allow top-side TEC and radio-occultation profiles to be recovered. The three-satellite constellation design is such that all local times at all geographic locations between 60°N and 60°S will be covered in a little more than one month, much faster than Swarm, which the NanoMagSat is also designed to complement for even better coverage, should Swarm still be in operation at the time of launch. After an initial Phase 0 study carried out with CNES support, NanoMagSat was next proposed in response to the ESA Scout call in 2019 and selected for a consolidation study, which ran through 2020. It is currently undergoing an ESA-funded 18 month phase of Risk Retirement Activities (RAA), aiming at being ready for a possible final selection in 2023, targeting a launch in 2025. This presentation will report on the way the project is currently moving forward technically, programmatically and scientifically. NanoMagSat is designed to complement and improve on many of the science goals of the Swarm mission at a much lower cost, also bringing innovative science capabilities for ionospheric investigations. It aims at forming the basis of a permanent collaborative INTERMAGSAT constellation of nanosatellites for low-cost long-term monitoring of the geomagnetic field and ionospheric environment from space, complementing the INTERMAGNET network of ground-based magnetic observatories. This presentation is also meant to initiate a discussion on the way the NanoMagSat project could contribute to the goals of the COSPAR Task Group on the Establishment of a Constellation of Small Satellites (COSPAR TGCSS)

NanoMagSat, a nanosatellite LEO constellation for monitoring Earth's magnetic field and ionospheric environment

International audienceThe geomagnetic field has been continuously monitored from low-Earth orbit (LEO) since 1999, complementing ground-based observatory data by providing calibrated scalar and vector measurements with global coverage. The successful ESA Swarm constellation is expected to remain in operation until at least 2025. Further monitoring the field from space with high-precision absolute magnetometry is of critical importance for improving our understanding of the dynamics of the multiple components of this field, as well as that of the ionospheric environment. The NanoMagSat project aims to deploy and operate a new LEO constellation with a current baseline of three identical 16U nanosatellites, using two 60° inclined orbits offset by 90° RAAN and one polar orbit, and hosting an innovative payload suite. This will consist of an advanced miniaturized absolute scalar and self-calibrated vector magnetometer (MAM) combined with a set of accurate star trackers (STR), a compact high-frequency field magnetometer (HFM), a multi-needle Langmuir probe (m-NLP) and dual frequency GNSS receivers. This payload suite will acquire high-precision/resolution oriented absolute vector magnetic data at 1 Hz sampling rate (for global magnetic field modelling purposes), very low noise scalar and vector magnetic field at 2 kHz (for ELF signal detection and down to decameter-scale local electrical currents monitoring), electron density data at 2 kHz (for very small scale plasma density investigations), as well as electron temperature at 1 Hz. GNSS receivers will also allow top-side TEC and radio-occultation profiles to be recovered. The three-satellite constellation design is such that all local times at all geographic locations between 60°N and 60°S will be covered in a little more than one month, much faster than Swarm, which the NanoMagSat is also designed to complement for even better coverage, should Swarm still be in operation at the time of launch. After an initial Phase 0 study carried out with CNES support, NanoMagSat was next proposed in response to the ESA Scout call in 2019 and selected for a consolidation study, which ran through 2020. It is currently undergoing an ESA-funded 18 month phase of Risk Retirement Activities (RAA), aiming at being ready for a possible final selection in 2023, targeting a launch in 2025. This presentation will report on the way the project is currently moving forward technically, programmatically and scientifically. NanoMagSat is designed to complement and improve on many of the science goals of the Swarm mission at a much lower cost, also bringing innovative science capabilities for ionospheric investigations. It aims at forming the basis of a permanent collaborative INTERMAGSAT constellation of nanosatellites for low-cost long-term monitoring of the geomagnetic field and ionospheric environment from space, complementing the INTERMAGNET network of ground-based magnetic observatories. This presentation is also meant to initiate a discussion on the way the NanoMagSat project could contribute to the goals of the COSPAR Task Group on the Establishment of a Constellation of Small Satellites (COSPAR TGCSS)

Statistical study of the GNSS phase scintillation associated with two types of auroral blobs

This study surveys space weather effects on GNSS (Global Navigation Satellite System) signals in the nighttime auroral and polar cap ionosphere using scintillation receivers, all-sky imagers, and the European Incoherent Scatter Svalbard radar. We differentiate between two types of auroral blobs: blob type 1 (BT 1) which is formed when islands of high-density F region plasma (polar cap patches) enter the nightside auroral oval, and blob type 2 (BT 2) which are generated locally in the auroral oval by intense particle precipitation. For BT 1 blobs we have studied 41.4 h of data between November 2010 and February 2014. We find that BT 1 blobs have significantly higher scintillation levels than their corresponding polar cap patch; however, there is no clear relationship between the scintillation levels of the preexisting polar cap patch and the resulting BT 1 blob. For BT 2 blobs we find that they are associated with much weaker scintillations than BT 1 blobs, based on 20 h of data. Compared to patches and BT 2 blobs, the significantly higher scintillation level for BT 1 blobs implies that auroral dynamics plays an important role in structuring of BT 1 blobs. © 2016. American Geophysical Union

NanoMagSat, a Low-Earth orbiting nanosatellite constellation to investigate Earth's magnetic field and ionospheric environment

International audienceThe geomagnetic field has been continuously monitored from low-Earth orbit (LEO) since 1999, complementing ground-based observatory data by providing absolute calibrated scalar and vector measurements with global planetary coverage. Such absolute magnetic vector data have proven critical for our ability to make progress in our understanding of the many sources of the Earth's magnetic field, their dynamics and the way they interact. Combined with data from adequate complementary payloads, these data can also be used to monitor the ionospheric environment. The information they provide is also massively used for many applications, ranging from orientation needs to space weather monitoring as well as, e.g., reconstructing Earth's crustal and mantle electrical conductivity. Ensuring continuity and improvement of such observations is therefore critical.Here, we will provide an overview of the current status and many science objectives of the NanoMagSat project, which aims to deploy and operate a new constellation concept of three identical 16U nanosatellites, using two inclined (approximately 60°) and one polar LEO, designed to complement and ensure continuity of the ongoing ESA Swarm mission at a much lower cost, and to also provide new science opportunities. This mission was proposed to ESA within the context of its Scout program, and is currently undergoing a 18 months Risk Retirement Activity phase funded by ESA, due to end in July 2023 and aiming at implementation for a launch possibly as early as 2026.The three-satellite constellation design is such that all local times at all geographic locations between 60°N and 60°S will be covered in a little more than one month, much faster than Swarm, which the NanoMagSat is also designed to complement for even better coverage, should Swarm still be in operation at the time of launch. Each satellite will carry an innovative payload including an advanced Miniaturized Absolute scalar and self-calibrated vector Magnetometer (MAM) combined with a set of precise star trackers (STR), a compact High-frequency Field Magnetometer (HFM), a multi-needle Langmuir Probe (m-NLP) and dual frequency GNSS receivers. This payload suite will acquire high-precision/resolution oriented absolute vector magnetic data at 1 Hz sampling rate (for global magnetic field modelling purposes), very low noise scalar and vector magnetic field at 2 kHz (for ELF signal detection and down to decameter-scale local electrical currents monitoring), electron density data at 2 kHz (for very small scale plasma density investigations), as well as electron temperature at 1 Hz. GNSS receivers will also allow top-side TEC and radio-occultation profiles to be recovered. Possibility of using the STRs to further recover energetic proton omnidirectional flux (above 100 MeV) is also considered.This presentation will also report on the way the science preparation of the project is currently moving forward with the help of its growing Science international team. On the longer term, NanoMagSat aims at forming the basis of a permanent collaborative INTERMAGSAT constellation of nanosatellites for low-cost long-term monitoring of the geomagnetic field and ionospheric environment from space, complementing the INTERMAGNET network of ground-based magnetic observatories

On the future NanoMagSat LEO nanosatellite constellation observations of space environment

International audienceThe NanoMagSat project aims to deploy and operate a new constellation concept of three identical 16U gravitygradient stabilized nanosatellites with no propulsion but stable enough attitude control, using two inclined (~ 60°) and one polar LEO, for investigating both the Earth’s magnetic field and the ionospheric environment. Drawing from the lessons learnt from the ESA Swarm mission, which it is designed to complement and succeed, it will also provide new science opportunities thanks to its innovative constellation design and miniaturized payload

On the future NanoMagSat LEO nanosatellite constellation observations of space environment

International audienceThe NanoMagSat project aims to deploy and operate a new constellation concept of three identical 16U gravitygradient stabilized nanosatellites with no propulsion but stable enough attitude control, using two inclined (~ 60°) and one polar LEO, for investigating both the Earth’s magnetic field and the ionospheric environment. Drawing from the lessons learnt from the ESA Swarm mission, which it is designed to complement and succeed, it will also provide new science opportunities thanks to its innovative constellation design and miniaturized payload